Folate deficiency modifies the risk of CIN3+ associated with DNA methylation levels: a nested case-control study from the ASCUS-COL trial.

PURPOSE: To our knowledge, there are very few studies evaluating if the levels of folate modify the risk of cervical intraepithelial neoplasia grade 2 and higher (CIN2+ and CIN3+) associated with the levels of HPV genome methylation, two cofactors related to single carbon metabolism and independently associated with cervical cancer in previous studies. We conducted a case-control study nested in a three-arm randomized clinical pragmatic trial (ASCUS-COL trial) to evaluate the risk of CIN3+ associated with methylation levels according to serum folate concentrations. METHODS: Cases (n = 155) were women with histologically confirmed CIN2+ (113 CIN2, 38 CIN3, and 4 SCC) and controls were age and follow-up time at diagnosis-matched women with histologically confirmed ≤ CIN1 (n = 155), selected from the 1122 hrHPV + women of this trial. The concentrations of serum folate were determined by the radioimmunoassay SimulTRAC-SNB-VitaminB12/Folate-RIAKit and the methylation levels by the S5 classifier. Stepwise logistic regression models were used to estimate the association between folate or methylation levels and CIN2+ or CIN3+. The joint effect of folate levels and methylation on the risk of CIN3+ was estimated using combinations of categorical stratifications. RESULTS: Folate levels were significantly lower in women with CIN3+ than in other diagnostic groups (p = 0.019). The risk of CIN3+ was eight times higher (OR 8.9, 95% CI 3.4-24.9) in women with folate deficiency and high methylation levels than in women with normal folate and high methylation levels (OR 1.4, 95% CI 0.4-4.6). CONCLUSION: High methylation and deficient folate independently increased the risk of CIN3+ while deficient folate combined with high methylation was associated with a substantially elevated risk of CIN3+.

Performance of an affordable urine self-sampling method for human papillomavirus detection in Mexican women.

INTRODUCTION: Urine self-sampling for human papillomavirus (HPV)-based cervical cancer screening is a non-invasive method that offers several logistical advantages and high acceptability, reducing barriers related to low screening coverage. This study developed and evaluated the performance of a low-cost urine self-sampling method for HPV-testing and explored the acceptability and feasibility of potential implementation of this alternative in routine screening. METHODS: A series of sequential laboratory assays examined the impact of several pre-analytical conditions for obtaining DNA from urine and subsequent HPV detection. Initially, we assessed the effect of ethylaminediaminetetraacetic acid (EDTA) as a DNA preservative examining several variables including EDTA concentration, specimen storage temperature, time between urine collection and DNA extraction, and first-morning micturition versus convenience sample collection. We further evaluated the agreement of HPV-testing between urine and clinician-collected cervical samples among 95 women. Finally, we explored the costs of self-sampling supplies as well as the acceptability and feasibility of urine self-sampling among women and healthcare workers. RESULTS: Our results revealed higher DNA concentrations were obtained when using a 40mM EDTA solution, storing specimens at 25°C and extracting DNA within 72 hrs. of urine collection, regardless of using first-morning micturition or a convenience sampling. We observed good agreement (Kappa = 0.72) between urine and clinician-collected cervical samples for HPV detection. Furthermore, urine self-sampling was an affordable method (USD 1.10), well accepted among cervical cancer screening users, healthcare workers, and decision-makers. CONCLUSION: These results suggest urine self-sampling is feasible and appropriate alternative for HPV-testing in HPV-based screening programs in lower-resource contexts.

Effective methylation triage of HPV positive women with abnormal cytology in a middle-income country.

The S5-methylation test, an alternative to cytology and HPV16/18 genotyping to triage high-risk HPV-positive (hrHPV+) women, has not been widely validated in low-middle-income countries (LMICs). We compared S5 to HPV16/18 and cytology to detect cervical intraepithelial neoplasia Grade 2 or worse (CIN2+) and CIN3+ in hrHPV+ women selected from a randomized pragmatic trial of 2661 Colombian women with an earlier-borderline abnormal cytology. We included all hrHPV+ CIN2 and CIN3+ cases (n = 183) age matched to 183

Adjunctive testing by cytology, p16/Ki-67 dual-stained cytology or HPV16/18 E6 oncoprotein for the management of HPV16/18 screen-positive women.

High-risk human papillomavirus type 16/18 (HPV16/18) genotyping is unable to accurately discriminate nonprogressive infections from those that will progress to cervical cancer. Our study aimed to assesses if additional testing either with liquid-based cytology (LBC) or the putative progression markers p16/Ki-67 and HPV16/18 E6 oncoprotein (E6) can improve the efficiency of HPV16/18 genotyping for triaging high-risk HPV (hrHPV)-positive women through better cancer risk stratification. Women attending colposcopy after positive HPV16/18 genotyping results within the Forwarding Research for Improved Detection and Access for Cervical Cancer Screening and Triage (FRIDA) hrHPV-based screening study in Tlaxcala, Mexico, underwent further testing with LBC, p16/Ki-67 dual-stained (DS) cytology and E6. We calculated measures of test performance for detecting histologically confirmed cervical intraepithelial neoplasia grade 2 or higher (CIN2+) and grade 3 or higher (CIN3+). A number of 475 (64.3%) of 739 HPV16/18-positive women had complete results for all tests. Triage positivity rates were 14.1%, 18.5% and 24.4%, for LBC, E6 and DS, respectively. Compared with LBC, DS had higher sensitivity (24.4% vs 60.0%) although lower specificity (87.0% vs 79.3%) for CIN3+ (P < .001), whereas E6 had a sensitivity of 37.8% and a specificity of 83.5%. No invasive cancer was missed by DS or E6, but 75% were in normal cytology. DS test was associated with nearly 75% reduction of colposcopy referrals compared with the direct referral of all HPV16/18-positive women, giving the least number of colposcopies (n = 4.3) per CIN3+ detected. We show that adjunctive testing of HPV16/18-positive women with DS may greatly reduce unnecessary colposcopy referrals within HPV-based screening employing HPV16/18 genotyping while retaining acceptable sensitivity for CIN2+ and CIN3+.

Comparison of HPV-16 and HPV-18 Genotyping and Cytological Testing as Triage Testing Within Human Papillomavirus-Based Screening in Mexico.

Importance: Triage tests enhance the efficiency cervical cancer screening based on human papillomavirus (HPV), but the best approach for maximizing programmatic effectiveness is still uncertain, particularly in a real-world scenario. Objective: To compare the clinical performance of 6 triage strategies based on liquid-based cytology (LBC) and HPV-16 and HPV-18 genotyping individually or in combination as sequential triage tests to detect cervical intraepithelial neoplasia (CIN) grade 2 or higher among women with high-risk HPV. Design, Setting, and Participants: This diagnostic study of routine cervical cancer screening was conducted at 100 primary health centers in Tlaxcala, Mexico. Women aged 30 to 64 years were recruited from August 1, 2013, to February 24, 2016, as part of the Forwarding Research for Improved Detection and Access for Cervical Cancer Screening and Triage study. Six triage scenarios for referral to colposcopy were examined: (1) LBC testing that found atypical squamous cells of undetermined significance (ASC-US) or worse, (2) positive results in HPV-16 genotyping, (3) positive results in HPV-18 genotyping, (4) positive results in HPV-16/HPV-18 genotyping, (5) positive results in HPV-16 genotyping or, if genotyping results were negative, reflex LBC testing that found ASC-US or worse, and (6) positive results in HPV-16/HPV-18 genotyping or, if genotyping results were negative, reflex LBC testing that found ASC-US or worse. Data were analyzed from October 2017 to August 2018. Exposures: Liquid-based cytological testing with simultaneous HPV-16 and HPV-18 genotyping. Women whose HPV genotyping results were positive for HPV-16 or HPV-18 or whose LBC results found ASC-US or worse and a random set of negative and normal results were referred to colposcopy with histologic analysis used for disease confirmation. Main Outcomes and Measures: Clinical performance of each test strategy for detection of CIN grade 2 or higher. Secondary outcomes included resource utilization of each triage scenario, measured by the number of tests performed, the referral rate for colposcopy, and the numbers of colposcopies per CIN grade 2 or higher detected. Results: A total of 36 212 women (median [interquartile range] age, 40 [35-47] years) were screened, and 4051 women (11.2%) had high-risk HPV. Of these women, 1109 (24.6%) were found to have HPV-16, HPV-18, or ASC-US or worse. Further histologic testing detected CIN grade 2 or higher in 110 of 788 women (14.0%) who underwent follow-up colposcopy. Sensitivity and specificity for 3 main triage strategies were 42.9% and 74.0% for LBC; 58.3% and 54.4% for HPV-16/HPV-18 genotyping; and 86.6% and 34.0% for HPV-16/HPV-18 genotyping with reflex LBC. The referral rate to colposcopy was 29% for HPV-16/HPV-18 with reflex LBC, which was 2-fold higher than the referral rate of 12% for LBC. Conclusions and Relevance: Triage of women with high-risk HPV with HPV-16/HPV-18 genotyping with reflex LBC was significantly associated with improvement in detection of CIN grade 2 or higher compared with LBC alone. The benefit of disease prevented may outweigh the cost of increasing requirements for colposcopy services in settings with limited adherence to follow-up after a positive screening result.

Methylation estimates the risk of precancer in HPV-infected women with discrepant results between cytology and HPV16/18 genotyping.

BACKGROUND: Vigilant management of women with high-risk human papillomavirus (hrHPV) is necessary in cancer screening programs. To this end, we evaluated the performance of S5 (targeting DNA methylation in HPV16, HPV18, HPV31, HPV33, and human gene EPB41L3) to predict cervical intraepithelial neoplasia grade 2 or higher (CIN2+) in a sample of hrHPV-infected women referred to colposcopy in the FRIDA Study, a large screening trial in Mexico. A nested case-control sample with women referred to colposcopy either by atypical squamous cells of undetermined significance or higher (ASCUS+) in cytology and/or positive for HPV types 16 or 18 was tested by S5. Seventy-nine cases of CIN2+ were age-matched to 237 controls without a diagnosis of CIN2+ (

Barriers to HPV self-sampling and cytology among low-income indigenous women in rural areas of a middle-income setting: a qualitative study.

BACKGROUND: Data is needed about barriers to self-collection of Human Papillomavirus (HPV) samples and cytology among low-income, disadvantaged women living in rural areas of lower-income countries as these women are at increased risk of cervical cancer mortality. METHODS: Individual interviews (n = 29), focus groups (n = 7, 5-11 participants) and discussion groups (n = 2, 18-25 participants) were organized with women from three indigenous ethnic groups residing in rural areas in Mexico, after they were provided with free, self-sampled HPV tests. These groups are low-income, underserved by healthcare and have historically been on the receiving end of racism and social exclusion. Descriptive, qualitative content analysis was done, including two cycles of coding. RESULTS: Interview and focus/discussion group data indicate women had limited understanding of HPV's role in cervical cancer etiology. They identified HPV's existence, that cytology detects cervical cancer, the need for regular testing and that cervical cancer is sexually transmitted. Organizational barriers to clinic-based cytology included irregular supplies of disposable speculums, distance to clinics and lack of clear communication by healthcare personnel. Women considered self-collected HPV-testing easy, less embarrassing and less painful than cytology, an opportunity for self-care and most felt they understood how to take a self-sample after a 20-min explanation. Some women feared hurting themselves when taking the self-sample or that they would take the sample incorrectly, which they worried would make the test useless. Attending HPV-testing in groups facilitated use by allowing women to discuss their doubts and fears before doing self-collection of the sample or to ask other women who were the first to do the self-sampling what the experience had been like (whether it hurt and how easy it was). Lack of indoor bathrooms was a barrier to doing HPV self-sampling at home, when those homes were resource-poor (one-room dwellings). CONCLUSIONS: Low-income, indigenous Mexican women residing in rural, underserved areas identified their need for cervical cancer screening but encountered multiple barriers to cytology-based screening. They found a number of advantages of HPV self-sampled tests. Employing self-collected HPV-testing instead of cytology could resolve some but not all gender-related, organizational or technical quality-of-care issues within cervical cancer detection and control programs.

Population-based prevalence of cervical infection with human papillomavirus genotypes 16 and 18 and other high risk types in Tlaxcala, Mexico.

BACKGROUND: Cervical cancer remains an important cause of cancer mortality for Mexican women. HPV 16/18 typing may help to improve cervical cancer screening. Here we present the prevalence of high-risk human papillomavirus (hrHPV) including HPV16 and HPV18 from the FRIDA (Forwarding Research for Improved Detection and Access) population. METHODS: Beginning in 2013, we recruited 30,829 women aged 30-64 in Tlaxcala, Mexico. Cervical samples were collected and tested for 14 hrHPV genotypes (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68). We used logistic regression to estimate odds ratios with 95 % confidence intervals for hrHPV infections according to putative risk factors. RESULTS: Prevalence of infection with any of the 14 hrHPV types was 11.0 %. The age-specific prevalence of all hrHPV formed a U-shaped curve with a higher prevalence for women aged 30-39 and 50-64 than women aged 40-49. Across all age groups, 2.0 % of women were positive for HPV16 and/or HPV18 (HPV16/18), respectively. HPV16/18 prevalence also showed a U-shaped curve with increased prevalence estimates for women aged both 30-39 and 60-64. Both prevalence curves had a significant quadratic age coefficient. Infections with hrHPV were positively associated with an increased number of lifetime sexual partners, a history of sexually transmitted disease, being unmarried, use of hormonal contraception, having a history of smoking and reported condom use in the multivariate model. CONCLUSIONS: The FRIDA population has a bimodal distribution of both hrHPV and HPV16/18 positivity with higher prevalences at ages 30-39 and 60-64. These findings will help to evaluate triage algorithms based on HPV genotyping. TRIAL REGISTRATION: The trial is registered with ClinicalTrials.gov, number NCT02510027 .

Triage strategies in cervical cancer detection in Mexico: methods of the FRIDA Study.

OBJECTIVE: This paper describes the study design and baseline characteristics of the study population, including the first 30 829 women who enrolled in the Forwarding Research for Improved Detection and Access for Cervical Cancer Screening and Triage (FRIDA Study). This is a large population based study that is evaluating the performance and cost-effectiveness of different triage strategies for high-risk HPV (hrHPV) positive women in Mexico. MATERIALS AND METHODS: The target population is more than 100 000 women aged 30 to 64 years who attend the Cervical Cancer Screening Program in 100 health centers in the state of Tlaxcala, Mexico. Since August 2013, all women in the region have been invited to enroll in the study. The study participants are evaluated to determine hrHPV infection using the Cobas 4800 HPV test. The HPV-16/18 genotyping and cytology triage strategies are performed as reflex tests in all hrHPV-positive participants. Women with a positive HPV-16/18 test and/or abnormal cytology (atypical squamous cells of undetermined significance or worse, ASCUS+) are referred for colposcopy evaluation, where a minimum of four biopsies and an endocervical sample are systematically collected. Histologic confirmation is performed by a standardized panel of pathologists. RESULTS: Among the 30 829 women who have been screened, the overall prevalence of hrHPV is 11.0%. The overall prevalence of HPV16 and HPV18 are 1.5% and 0.7%, respectively. Cytological abnormalities (ASCUS+) were detected in 11.8% of the hrHPV-positive women. A total of 27.0% (920/3,401) of the hrHPV-positive women were referred to colposcopy because of a positive HPV16/18 test and/or abnormal reflex cytology, (31.6% had only ASCUS+, 53.6% were HPV16/18 positive with a normal cytology result, and 9.5% were positive to both triage tests). CONCLUSION: The results of this study will help policy makers and health service providers establish the best practices for triage in cervical cancer screening in Mexico and other countries.

HPV vaccination impact on a cervical cancer screening program: methods of the FASTER-Tlalpan Study in Mexico.

OBJECTIVE: To outline the design of a clinical trial to evaluate the impact of HPV vaccination as part of a hrHPV-based primary screening program to extend screening intervals. MATERIALS AND METHODS: A total of 18,000 women aged 25-45 years, attending the regular cervical cancer-screening program in primary health care services in Tlalpan, Mexico City, will be invited to the study. Eligible participants will be assigned to one of three comparison groups: 1) HPV16/18 vaccine and hrHPV-based screening; 2) HPV6/11/16/18 vaccine and hrHPV-based screening; 3) Control group who will receive only hrHPV-based screening. Strict surveillance of hrHPV persistent infection and occurrence of precancerous lesions will be conducted to estimate safety profiles at different screening intervals; participants will undergo diagnosis confirmation and treatment as necessary. CONCLUSION: The FASTER-Tlalpan Study will provide insights into new approaches of cervical cancer prevention programs. It will offer valuable information on potential benefits of combining HPV vaccination and hrHPV-based screening to safety extend screening intervals.

HPV vaccination impact on a cervical cancer screening program: methods of the FASTER-Tlalpan Study in Mexico / Impacto de la vacunación de VPH en un programa de tamizaje de cáncer cervical: métodos del Estudio FASTER-Tlalpan en México

Abstract Objective: To outline the design of a clinical trial to evaluate the impact of HPV vaccination as part of a hrHPV-based primary screening program to extend screening intervals. Materials and methods: A total of 18,000 women aged 25-45 years, attending the regular cervical cancer-screening program in primary health care services in Tlalpan, Mexico City, will be invited to the study. Eligible participants will be assigned to one of three comparison groups: 1) HPV16/18 vaccine and hrHPV-based screening; 2) HPV6/11/16/18 vaccine and hrHPV-based screening; 3) Control group who will receive only hrHPV-based screening. Strict surveillance of hrHPV persistent infection and occurrence of precancerous lesions will be conducted to estimate safety profiles at different screening intervals; participants will undergo diagnosis confirmation and treatment as necessary. Conclusion: The FASTER-Tlalpan Study will provide insights into new approaches of cervical cancer prevention programs. It will offer valuable information on potential benefits of combining HPV vaccination and hrHPV-based screening to safety extend screening intervals.

Resumen Objetivo: Describir los métodos de un ensayo clínico que permita evaluar el impacto de la incorporación de la vacunación contra VPH en el programa de detección oportuna de cáncer cervical con el fin de ampliar los intervalos de tamizaje. Material y métodos: Un total de 18 000 mujeres entre 25 y 45 años, usuarias del programa de detección oportuna de cáncer cervical de la Ciudad de México en Tlalpan, serán invitadas a participar en el estudio. Las mujeres elegibles serán aleatorizadas a uno de tres grupos de comparación: 1) Vacunación contra VPH16/18 y tamizaje con VPHar; 2) Vacunación contra VPH6/11/16/18 y tamizadas con VPHar; 3) Grupo control que será sólo tamizado con VPHar. Se llevará a cabo una estrecha vigilancia de la infección persistente de VPHar y de la ocurrencia de lesiones precancerosas, con el fin de estimar el perfil de seguridad de intervalos de tamizaje de distinta duración. Todas las participantes contarán con procedimientos de confirmación diagnóstica y tratamiento en caso necesario. Conclusión: El estudio FASTER-Tlalpan introducirá una nueva visión de la implementación de nuevos abordajes en la prevención de cáncer cervical. Ofrecerá información de los potenciales beneficios de la combinación de la vacunación contra VPH y el tamizaje basado en VPHar para extender los intervalos de tamizaje.

Triage strategies in cervical cancer detection in Mexico: methods of the FRIDA Study / Estrategias de triage en la detección de cáncer cervical: métodos del estudio FRIDA

Abstract Objective: This paper describes the study design and baseline characteristics of the study population, including the first 30 829 women who enrolled in the Forwarding Research for Improved Detection and Access for Cervical Cancer Screening and Triage (FRIDA Study). This is a large population based study that is evaluating the performance and cost-effectiveness of different triage strategies for high-risk HPV (hrHPV) positive women in Mexico. Materials and methods: The target population is more than 100 000 women aged 30 to 64 years who attend the Cervical Cancer Screening Program in 100 health centers in the state of Tlaxcala, Mexico. Since August 2013, all women in the region have been invited to enroll in the study. The study participants are evaluated to determine hrHPV infection using the Cobas 4800 HPV test. The HPV-16/18 genotyping and cytology triage strategies are performed as reflex tests in all hrHPV-positive participants. Women with a positive HPV-16/18 test and/or abnormal cytology (atypical squamous cells of undetermined significance or worse, ASCUS+) are referred for colposcopy evaluation, where a minimum of four biopsies and an endocervical sample are systematically collected. Histologic confirmation is performed by a standardized panel of pathologists. Results: Among the 30 829 women who have been screened, the overall prevalence of hrHPV is 11.0%. The overall prevalence of HPV16 and HPV18 are 1.5% and 0.7%, respectively. Cytological abnormalities (ASCUS+) were detected in 11.8% of the hrHPV-positive women. A total of 27.0% (920/3,401) of the hrHPV-positive women were referred to colposcopy because of a positive HPV16/18 test and/or abnormal reflex cytology, (31.6% had only ASCUS+, 53.6% were HPV16/18 positive with a normal cytology result, and 9.5% were positive to both triage tests). Conclusion: The results of this study will help policy makers and health service providers establish the best practices for triage in cervical cancer screening in Mexico and other countries.

Resumen Objetivo: El objetivo de este artículo es describir el diseño del estudio FRIDA y las características basales de las primeras 30 829 mujeres tamizadas. El estudio FRIDA (Forwarding Research for Improved Detection and Access for Cervical Cancer Screening and Triage) es un estudio de demostración con base poblacional diseñado para evaluar el desempeño y costo-efectividad de diferentes alternativas de triage en mujeres VPH de alto riesgo (VPHar) positivas bajo condiciones reales de un programa de tamizaje para cáncer cervical en México. Material y métodos: La población objetivo la conforman poco más de 100 000 mujeres de 30 a 64 años que asisten al programa de detección oportuna de cáncer cervical en alguno de los 100 centros de salud de la jurisdicción sanitaria 1 de Tlaxcala. Desde agosto de 2013, todas las mujeres son invitadas al estudio. Las participantes del estudio son tamizadas para determinar la infección con VPHar mediante la prueba VPHar Cobas 4800. Se realizan las pruebas de triage de tipificación de VPH16/18 y citología en todas las mujeres con resultados VPHar positivos. Las mujeres con un resultado positivo a VPH16/18 y/o citología anormal (células escamosas atípicas de resultado incierto o peor: ASCUS+) son referidas a evaluación colposcópica, seguida de una colección sistemática de un mínimo de cuatro biopsias cervicales y un cepillado endocervical. La confirmación histológica se lleva a cabo por un panel de patólogos. Resultados Un total de 30 829 mujeres han sido tamizadas, con una prevalencia de VPHar del 11.0%. La prevalencia global de VPH16 y VPH18 es 1.5% y 0.7%, respectivamente. Se detectó un 11.8% de anormalidades citológicas (ASCUS+). Entre las mujeres VPHar positivas, la prevalencia de un resultado de triage positivo (VPH16/18 o citología anormal) fue 27.0%, distribuido de la siguiente forma, 31.6% de éstos fueron sólo ASCUS+ VPH16/18 negativo, 53.6% fueron VPH 16/18 positivos y citología normal, y 9.5% positivos a ambas pruebas de triage. Conclusión: Los resultados de este estudio ayudarán tanto a los tomadores de decisiones como a los proveedores de servicios de salud a establecer la mejor estrategia de triage en programas de tamizaje de cáncer cervical basados en VPHar en México y en otros países.

Specimen self-collection and HPV DNA screening in a pilot study of 100,242 women.

Since cervical cancer remains common in Mexico despite an established cytology screening program, the Ministry of Health recently introduced pilot front-line HPV testing into the Mexican cervical cancer screening program (CCSP). Here, we present the key field performance metrics of this population-based study. High-risk HPV DNA (hrHPV) testing was conducted on self-collected vaginal specimens from 100,242 women aged 25-75 years residing in Morelos State. All hrHPV positive women and a random sample of 3.2% (n = 2,864) of hrHPV negative participants were referred for colposcopic examination. The main disease endpoint of interest was cervical intraepithelial neoplasia grade 2 or higher (CIN2+). We calculated relative risk, positive predictive value and negative predictive value adjusted for screening test verification bias. The overall prevalence of hrHPV was 10.8% (95% CI 10.6-11.0). Women positive for hrHPV had a relative risk of 15.7 for histologically detectable CIN2+. The adjusted positive predictive value of the hrHPV test was 2.4% (95% CI 2.1-2.7); whereas the adjusted negative predictive value was 99.8% (95% CI 99.8-99.9). These findings suggest that large-scale vaginal hrHPV testing in a middle-income country can identify women at greater risk of advanced cervical abnormalities in a programmatically meaningful way but care is warranted to ensure that disease not detectable at colposcopy is kept to a minimum. PASS shows areas that need improvement and sets the stage for wider use of hrHPV screening of self-collected vaginal specimens in Mexico.

Methylation of human papillomavirus type 16 genome and risk of cervical precancer in a Costa Rican population.

BACKGROUND: Previous studies have suggested an association between human papillomavirus type 16 (HPV16) genome methylation and cervical intraepithelial neoplasia grade 3 (CIN3) (ie, cervical precancer) and cancer, but the results have been inconsistent. METHODS: We designed a case-control study within a large prospective cohort of women who underwent multiple screenings for cervical cancer in Guanacaste, Costa Rica. Diagnostic specimens were collected at the time of CIN3 diagnosis (n = 30 case subjects) and persistent HPV16 infection (persistence; n = 35 case subjects), prediagnostic specimens at the first HPV16-positive screening visit (n = 20 CIN3 case subjects; n = 35 persistence case subjects), and control specimens from women with infection clearance within 2 years (n = 34 control subjects). DNA extracted from specimens (cervical cells) was analyzed for methylation levels at 67 CpG sites throughout the HPV16 genome using pyrosequencing. Benjamini-Hochberg method was used to account for multiple testing. Associations between methylation levels and risk of CIN3 or persistence were assessed using logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Increased methylation in diagnostic vs control specimens at nine CpG sites, three in each L1, L2, and E2/E4 genomic regions, was associated with an increased risk of CIN3 (third tertile [high] vs first and second tertiles combined [low], OR = 3.29 [95% CI = 1.16 to 9.34] to 11.12 [95% CI = 2.29 to 76.80]) and persistence. High methylation at three of these CpG sites was associated with a much higher risk when combined compared with low methylation at these sites (OR = 52, 95% CI = 4.0 to 670). In prediagnostic vs control specimens, increased methylation at a CpG site (nucleotide position 4261) in L2 was associated with an increased risk of CIN3. CONCLUSION: In this HPV16-infected cohort, increased methylation of CpG sites within the HPV16 genome before diagnosis and at the time of diagnosis was associated with cervical precancer.

Self-collection of vaginal specimens for human papillomavirus testing in cervical cancer prevention (MARCH): a community-based randomised controlled trial.

BACKGROUND: Vaginal self-sampling for human papillomavirus (HPV) DNA testing could increase rates of screening participation. In clinic-based settings, vaginal HPV testing is at least as sensitive as cytology for detecting cervical intraepithelial neoplasia (CIN) grade 2 or worse; however, effectiveness in home settings is unknown. We aimed to establish the relative sensitivity and positive predictive value for HPV screening of vaginal samples self-collected at home as compared with clinic-based cervical cytology. METHODS: We did a community-based, randomised equivalence trial in Mexican women of low socioeconomic status aged 25-65 years. Participants came from 540 medically underserved, predominantly rural communities in Morelos, Guerrero, and the state of Mexico. Our primary endpoint was CIN 2 or worse, detected by colposcopy. We used a computer-generated randomisation sequence to randomly allocate patients to HPV screening or cervical cytology. Eight community nurses who were masked to patient allocation received daily lists of the women's names and addresses, and did the assigned home visits. We referred women with positive results in either test to colposcopy. We did per-protocol and intention-to-screen analyses. This trial was registered with the Instituto Nacional de Salud Pública, Mexico, INSP number 590. FINDINGS: 12,330 women were randomly allocated to HPV screening and 12,731 to cervical cytology; 9202 women in the HPV screening group adhered to the protocol, as did 11,054 in the cervical cytology group. HPV prevalence was 9·8% (95% CI 9·1-10·4) and abnormal cytology rate was 0·38% (0·23-0·45). HPV testing identified 117·4 women with CIN 2 or worse per 10,000 (95·2-139·5) compared with 34·4 women with CIN 2 or worse per 10,000 (23·4-45·3) identified by cytology; the relative sensitivity of HPV testing was 3·4 times greater (2·4-4·9). Similarly, HPV testing detected 4·2 times (1·9-9·2) more invasive cancers than did cytology (30·4 per 10,000 [19·1-41·7] vs 7·2 per 10,000 [2·2-12·3]). The positive predictive value of HPV testing for CIN 2 or worse was 12·2% (9·9-14·5) compared with 90·5% (61·7-100) for cytology. INTERPRETATION: Despite the much lower positive predictive value for HPV testing of self-collected vaginal specimens compared with cytology, such testing might be preferred for detecting CIN 2 or worse in low-resource settings where restricted infrastructure reduces the effectiveness of cytology screening programmes. Because women at these sites will be screened only a few times in their lives, the high sensitivity of a HPV screen is of paramount importance. FUNDING: Instituto Nacional de Salud Pública, the Health Ministry of Mexico, QiAGEN Corp.

HPV testing for cervical cancer screening appears more cost-effective than Papanicolau cytology in Mexico.

OBJECTIVE: To determine the incremental costs and effects of different HPV testing strategies, when compared to Papanicolau cytology (Pap), for cervical cancer screening in Mexico. METHODS: A cost-effectiveness analysis (CEA) examined the specific costs and health outcomes associated with (1) no screening; (2) only the Pap test; (3) only self-administered HPV; (4) only clinician administered HPV; and (5) clinician administered HPV plus the Pap test. The costs of self- and clinician-HPV testing, as well as with the Pap test, were identified and quantified. Costs were reported in 2008 US dollars. The health outcome associated with these screening strategies was defined as the number of high-grade cervical intraepithelial neoplasia or cervical cancer cases detected. This CEA was performed using the perspective of the Mexican Institute of Social Security (IMSS) in Morelos, Mexico. RESULTS: Screening women between the ages of 30-80 for cervical cancer using clinical-HPV testing or the combination of clinical-HPV testing, and the Pap is always more cost-effective than using the Pap test alone. CONCLUSIONS: This CEA indicates that HPV testing could be a cost-effective screening alternative for a large health delivery organization such as IMSS. These results may help policy-makers implement HPV testing as part of the IMSS cervical cancer screening program.

A pilot study of HPV DNA and cytology testing in 50,159 women in the routine Mexican Social Security Program.

INTRODUCTION: We present a large feasibility evaluation of high-risk HPV (HR-HPV) DNA testing and cervical cytology as a primary screening strategy for cervical cancer precursor lesions in Mexican women, as part of a routine cancer control program (CCP). METHODS: A community-based study was carried out in 50,159 women aged 20-70 years who visited the CCP in 12 federal entities located in Northern, Central, and Southern Mexico, including a total of 48 primary health care units of the Instituto Mexicano del Seguro Social (IMSS). Cervical specimens for cytology and HR-HPV tests were collected at baseline. Women with cytological abnormalities (ASCUS or greater) were referred to colposcopy for further evaluation and treatment if necessary. A subset of HR-HPV-positive women without cervical lesions, in Morelos state, were tested again for HR-HPV DNA within a year, and repeat-positive women were referred to colposcopy. RESULTS: HR-HPV prevalence among all women was 8.6% (95% CI: 8.3-8.9). Prevalence by age group was 12.2% (95% CI: 11.0-13.3) before 30 years of age and decreased to 7.4% (95% CI: 6.7-8.0) between 46 and 50 years of age. A second minor prevalence peak (8.1%; 95% CI: 7.2-9.0) was observed in women more than 55 years of age. Overall prevalence of cytological abnormalities was relatively low (2.2%; 95% CI: 2.0-2.3) with the highest frequency of abnormal cytology (ASCUS or greater) in the 41-45 year age group (2.5%: 95% CI 2.1-2.7). No correlation between cervical abnormalities and HR-HPV prevalence, by region, was observed. A total of 370 (0.7%) women had an abnormal cytology as well as a positive HR-HPV result; 736 (1.5%) had an abnormal cytology and a negative HR-HPV test; 3,941 (7.9%) women had a positive HR-HPV test and a normal cytology; and 45,112 (89.9%) women were negative in both tests. The first two groups were immediately referred to colposcopy, 72.7% of the women from the cytology-positive and HR-HPV-positive group and 58.0% from the cytology-positive and HR-HPV-negative group successfully completing evaluation. Among the 269 cytology-positive and HR-HPV-positive women, 53 (19.7%) CIN2/3+ cases were detected, whereas among the 427 cytology-positive and HR-HPV-negative participants, only 13 (3.0%) CIN2/3+ cases were documented. In Morelos state, a sample of 287 women with a negative cytology smear and a positive HR-HPV test at baseline were re-screened after ~12 months, by means of cytology and HR-HPV testing. Among these women, 106 (36.9%) were again HR-HPV positive and were referred to colposcopy. Of whom, 76 (71.7%) were successfully evaluated; among these women, 9 CIN2/3+ (11.8%) were documented. Sensitivity of cervical cytology for detecting histologically confirmed CIN2/3+ cases was only 40.0% (95% CI 38.5-41.4) compared to 93.3% (95% CI 92.5-94.0) for HPV DNA testing considering the additional cases detected among women with persistent HPV infection. The specificity of cytology was 97.0 vs. 89.2% for the HPV DNA test. DISCUSSION: Population-based programs using HR-HPV testing can improve cervical cancer prevention and control in Mexican and other populations where cytological screening is inadequate for detecting precursors of cervical cancer.

Risk factors for cervical cancer among HPV positive women in Mexico.

OBJECTIVE: To identify factors that are associated with an increased risk of developing high-grade cervical intraepithelial neoplasia (CIN) or cancer among human papillomavirus (HPV)-positive women in Mexico. MATERIAL AND METHODS: A case-control study design was used. A total of 94 cases and 501 controls who met the study inclusion criteria were selected from the 7 732 women who participated in the Morelos HPV Study from May 1999 to June 2000. Risk factor information was obtained from interviews and from HPV viral load results. Odds ratios and 95 percent confidence intervals were estimated using unconditional multivariate regression. RESULTS: Increasing age, high viral load, a young age at first sexual intercourse, and a low socio-economic status are associated with an increased risk of disease among HPV-positive women. CONCLUSIONS: These results could have important implications for future screening activities in Mexico and other low resource countries.

Risk factors for cervical cancer among HPV positive women in Mexico / Factores de riesgo de cáncer cervical en mujeres VPH positivas en México

OBJECTIVE: To identify factors that are associated with an increased risk of developing high-grade cervical intraepithelial neoplasia (CIN) or cancer among human papillomavirus (HPV)-positive women in Mexico. MATERIAL AND METHODS: A case-control study design was used. A total of 94 cases and 501 controls who met the study inclusion criteria were selected from the 7 732 women who participated in the Morelos HPV Study from May 1999 to June 2000. Risk factor information was obtained from interviews and from HPV viral load results. Odds ratios and 95 percent confidence intervals were estimated using unconditional multivariate regression. RESULTS: Increasing age, high viral load, a young age at first sexual intercourse, and a low socio-economic status are associated with an increased risk of disease among HPV-positive women. CONCLUSIONS: These results could have important implications for future screening activities in Mexico and other low resource countries.

OBJETIVO: Identificar factores asociados con un mayor riesgo de desarrollar neoplasia intraepitelial cervical (NIC) de alto grado o cáncer en mujeres con virus de papiloma humano (VPH), en México. MATERIAL Y MÉTODOS: Se utilizó un diseño de casos y controles. Un total de 94 casos y 501 controles fueron seleccionados de las 7 732 mujeres que participaron en el Estudio de VPH en Morelos, de mayo de 1999 a junio de 2000. La información sobre factores de riesgo se obtuvo de entrevistas y de los resultados de carga virales de VPH. Se estimaron razones de momios e intervalos de confianza de 95 por ciento con modelos multivariados de regresión no condicionada. RESULTADOS: El incremento de edad, la carga viral elevada, la edad temprana al inicio de la vida sexual y el nivel socioeconómico bajo se asocian con un mayor riesgo de enfermedad en mujeres VPH positivas. CONCLUSIONES: Estos resultados podrían tener implicaciones importantes a futuro para las actividades de tamizaje en México y en otros países de bajos recursos.

[Assessment of HPV detection assays for use in cervical cancer screening programs]. / Evaluación de las técnicas de detección del VPH en los programas de cribado para cáncer de cuello uterino.

OBJECTIVE: Detection of high-risk human papillomavirus types (HPV) infection is an important tool in the screening of cervical cancer and triage of cytological abnormalities. The different techniques for detection of this cancer need to be contrasted and validated for use in population screening. MATERIAL AND METHODS: Cervical cell samples were collected from 166 women attending a dermatology clinic in Oviedo (Spain). We evaluated the performance of three different assays for VPH detection. The methods utilized were 1) In-house PCR-EIA using LI consensus primers MY09/ MY11, 2) A PCR-reverse line blot hybridization (PCR-LBH) that uses LI consensus PGMY primers. 3) Hybrid Capture 2. All assays were performed blinded. The kappa statistic was used to test for global agreement between assay pairs. RESULTS: HPV DNA was detected in 24,7%, 25,3% and 29,5% of the women, respective to the assay. The overall agreement between the in-house PCR, PCR-LBH and HC2 was (73.5%) with all kappa values between assay pairs exceeding 0.56 (p<0.001). CONCLUSION: The three HPV assays were equally accurate in estimating high-risk HPV prevalence and HPV-related lesions. The method for HPV detection must be decided depending on the goals of the search (screening, follow-up or molecular studies).